The CTC magazine used to put in articles from it’s early editions. One of these was a retired army major just after WWI who toured France on a tricycle. Being aware of how aggressive French farms dogs could be he had his service revolver stored in a handle bar mounted holster and shot three on his holiday. I imagine a tricycle would make a stable firing platform.
Not owning any firearms, my technique with aggressive dogs is to out run them if they come from behind or side. Weaving distracts the aim of biting fast dogs. If they’re in front then I drift towards the right, they track me, then when v close, I decleat my right leg turn as I turn sharply to the left, inevitably they’re trying to adjust and are off balance, so that when the heel of my straight right leg catches them in the shoulder and they go down. Shoulder is a better target than the head as with the head they may shrug off the blow and potentially bite back